This invention relates to terminal receptacle devices of the type which are commonly mounted on printed circuit boards and which receive leads from dual inline packages (DIP's) or other types of circuit packages mounted on the board.
It is common practice to produce printed circuit board assemblies by providing holes in the circuit board, mounting terminal receptacle devices in the holes and soldering the ends of the receptacle devices to the conductors on the circuit board. Circuit packages, such as DIP's are then connected to the circuit board conductors by inserting the leads from the DIP's into the receptacles.
A wide variety of these receptacle devices have been developed for use under all of the specific conditions encountered in the manufacture of circuit boards. For example, some circuit boards have holes which are plated, that is, the wall of the hole is provided with a thin plating of metal to connect conductor pads on opposite surfaces of the board and to facilitate soldering. Other circuit boards have unplated holes and require a different type of terminal than those used on boards having plated-through holes. To cite a further example, some receptacle terminals are intended to be mounted in insulating housings such that the leads from the terminals extend from the lower surface of the housing. The housings are assembled to the board by inserting the leads through holes in the board and then soldering, by wave soldering techniques, the leads to the circuit paths on the circuit board. Other terminals are specifically designed to be freestanding on the board, that is, they stand alone, and are not used in conjunction with a separate insulating housing. A further variation relates to the conductors on the printed circuit board; some circuit boards have conductors on only one side or the other (the upper or lower surface) and other circuit boards have conductors on both sides thereof and again, specialized receptacle terminals have been developed for each arrangement of the conductors on the board surface.
Some typical receptacle terminals which are being used or which have been proposed in the past are shown in U.S. Pat. Nos. 3,609,640, 3,673,551, 3,384,865, 3,718,895, 3,188,599, and 3,659,243. A review of the specifications of these patents, particularly those which were issued most recently will reveal some of the highly specialized conditions and problems which are addressed by the receptacle terminals shown therein.
The present invention is specifically directed to the achievement of a receptacle terminal having improved soldering characteristics, having improved spring means which permits it to accept leads of widely varying thicknesses, improved mounting means which provide a stable mounting on the circuit board, and a terminal device which can be produced at a moderate cost and inserted into the circuit board by automatic or semi-automatic insertion machines.
It is accordingly an object of the invention to provide an improved receptacle terminal for use on printed circuit boards. A further object is to provide a terminal device having an improved spring therein which permits the device to be used with leads of varying thicknesses. A further object is to provide a terminal device having improved soldering characteristics and which can be soldered to the board without risk of solder flow into the active portion of the terminals, that is, the portions including the spring which receive an inserted lead.